Dextran filament manufacture



pril 6, 1954 G. L. DENISTON 2,674,517

DEXTRAN FILAMENT MANUFACTURE Filed Aug. 8, 1951 I 3 INVENTOR g m Q m u) GEORGE, L. DENISTON N ATTORNEYS Patented Apr. 6, 1954 i 2,674,517

UNITED STATES PATENT OFFICE 2,674,517 DEXTRAN FILAMENT MANUFACTURE George L. Deniston, Dayton, Ohio, assignor to The Commonwealth Engineering Company of Ohio, Dayton, Ohio, a corporation of Ohio Application August 8, 1951, Serial No. 240,829

20 Claims. (o1.1s-s4) 1 This invention relates to the production of filarange for the material utilized in the practice ments and more particularly to the production of of this invention.

a resinated hydrolyzed dextran monofilament and A particularly suitable water soluble resin for l the method of attaining the same. the practice of invention is urea formaldehyde. f The present invention contemplates the 'pro- 5 While urea formaldehyde condensation products vision of a new and novel fiber having as the basic are preferred, melamine formaldehyde may also material a polysaccharide. The invention further be utilized. In the practice of the invention these contemplates the provision of a new and novel resins are simply mixed together with a mass of rocess utilizable for the attainment of the fiber dextran and water until complete dispersion of of invention. the resins throughout the mass is attained.

More particularly the invention conceives the The liquid medium which effects polymerization incorporation of a water soluble resin material of the resin is acidic in nature and may be weakly into a water soluble polysaccharide to form a or strongly acid in character depending upon the viscous mass which may be extruded under prestime of exposure of the dextran resinate thereto, sure and thereafter passed into a liquid medium and also upon the proportion of dextran relative which acts to polymerize the resin and firmly set to the resin quantity. The latter factor is parthe extruded filament, complete polymerization ticularly important wherethe dextran is present being effected by a subsequent heating step. The in the composition in large proportions, that is, filament produced is capable of use as a monofilagreater than about 75 0 by dry weight, as the rement having a diameter of about A" to but sultant mixture under these conditions may tend finer filaments having a diameter in the range of to dissolve in strong acids. The media which are .002 to .004 are within the contemplation of the particularly useful in the practice of the invenin e-nt o f precautions a taken to insure of tion are those which have a slightly acidic nature mediate gathering of the iine filamentsinto a tow and 1; precipitating media, for hydrolyzed directly after polymellzatlon of the resmdextran from aqueous solution. Thus acetone due The dextran referred to is a polysaccharide produced by the action of micro-organisms on a suitable culture medium and may be prepared by t a he extruded com ositlo in an inte ra uni forming a mixture containing sucrose that IS 1n m t n g 1 t to the acidic character of the alpha hydrogen may act to polymerize the resin and also serve to re- The lower aliphatic alcohols such as methyl, ethyl the form of crude sugar, molasses or the like, together with nitrogen in the form of commercial and prowl acldlfifgd Wlth a strong ac1d.t0 the expeptone, beef extract or other similar material, m of parifs by Weight of h and salts Such as dipotassium phosphate and acid may be utilized. Alternatively, weak orgamc dium chloride and inoculating with Leuconostoc acids such as normal acetic may be employed mesenteroides or Leuconostoc dextranicum. A W116re the exposure time Of the extruded OmDO typical medium may contain 5 to 10% of sucrose, on i low and the percent by weight of dextran 0.1% of peptone, 0.2% of dipotassium phosphate, in the composition less than about 50%. Boric and 0.1% of sodium chloride. The pH of the acid or lactic acid may also be employed. Salts medium is adjusted preferably slightly on the which yield a free acid upon heating, such as amalkaline side of neutrality. inonium salt and ammonium sulfate, may also be e no u d Culture y be incubated at a utilized and these act to effect complete polymertemperaturemost iavorable to the growth of the ization in the heating step micro-organism bemg used. For L. mesenterozdes The invention will be more fully understood by temperature, of about Q is suitable when reference to the following specific examples and the fermentation has been completed the polysacthe figures of the drawing wherein.

charide formed is precipitated from the culture Figure 1 is a diagrammatic representation of by the addition thereto of alcohol or acetone. The precipitate may be purified by further washing :2; apparatus used m the process of inventlon with alcohol or acetone.

The dextran thus produced may be redissolved F1gure 2 Illustrates moved f and hydrolyzed with acid and the solution frac- Refernflg to the f there 15 shown tionated by treatment with isopropyl alcohol to grammatlcauy at I a spmneretpontamel' having remove the high molecular constituents, leaving a therein a fiomposition containing he Water S0111- dextran having a molecular weight in the range ble dextran and the water soluble resin as indiof 50,000 to three million, which is the desired cated at 2. This composition comprises:

3 EXAMPLE 1 Deastran composition Per cent by weight Dextran (average molecular weight of 100,000) 60 Water 40 Resin composition Water soluble urea formaldehyde 50 Water 50 Pressure is applied to the mass at 2 by suitable means (not shown) known to. the art, to cause extrusion of filament 3,.which is immediately passed into a bath 50f, acetonecontained by the action of the acetone which also. begins,

immediately to polymerize the resin.

The filament While having strength will nevertheless be moderately plastic and is immediately wound around grooved roll 6 (Figure 2) and passed through the acetone to another grooved roll 1. Each of rolls 6 and I may be driven in synchronism and each may have 8 to 10 grooves. The driving speed of the rolls and the number of grooves employed will determine the time of contact of the filament with the acetone, the time generally increasing with the degree of polymerization required in this stage.

Where required, the roll 1 may be driven at a slightly greater peripheral speed than the roll 6', thus stretching the filament during the polymerization process and effecting an alignment of-the molecules. Normallythis practice may be employed and is recommended for all proportions of the composition making up the filament.

The time of contact employing the proportions of the constituents indicated abovemay be on the order of 7 to 9 minutes. The polymerization effected under these conditions is not complete but of the order to render the filament quite stable for further handling.

The filament is passed from the acetone bath over roll 8 into a water bath l0. contained in tank 9, rolls l2 and I l which are similar to ,rolls :6 andi being used tosupport the passage. This, water treatment removes the acetone which-might be detrimental to the filament under the high temperature conditions employed in the final polymerization step.

The filament free of acetone is passed through oven M operating at a temperature in the range of about 150 to 250 C. being supportedin the passing on rolls l3 and I5, whereafter it is wound up on roll 16. The oven temperature and speed may be coordinated to efiect complete-polymerization, a desirable temperature and speed relation in the present instance being a temperature of about 200 C. at a speed of about 2feet per minute, the length of the oven being about 18 feet. Where the oven traverse is long, as indicated in this instance; the;filament:may-be. supported intermediatethe-oveni ends; byadditional rolls as at H, or-mayeven'be-transported; on; an

open mesh screen.

The procedure of invention is similar in the preparation of finer fibers except the fibers of small diameter are, upon extrusion, blown, into a tow before passing into the acetone, in, the manner known to the art.

EXAMPLE. II Melamine formaldehyde, water soluble, may be regulated to about 3 to 5 minutes.

employed and a preferable composition in this instance may consist of:

Dextran composition Per cent by weight Dextran (average molecular weight of 350,000)

Water 15 Resin composition Water soluble melamine formaldehyde 70 Water 30 EXANIPLE III Analkylated urea formaldehyde resin may be employed with the dextran in the following proportions:

Demtmn composition Per cent by weight Dextran (average molecular Weight of 350,000) 85 Water 15 Resin composition Water soluble alkylated urea forma1dehyde 80 Water 20 The bath 5 may preferably contain 0.1 normal acetic acid and the time of passage therethrough After washing with water the filament may be treated at a temperature or about 235 C. in the oven, the time of treatment being about 2 to 4 minutes.

EXAMPLE IV A methylated methylol urea formaldehyde Water soluble resin may be employed with the dextran in the following proportions:

Dextran composition By weight Dextran (average molecular weight 3 million)- 40 Water 60 Resin composition Methylatedmethylol urea formaldehyde 65 Water 35 The bath 51113.3 contain a Molal solution of ammonium sulphate having about 0.5 of an equivalent of sulfuric acid. The time of passage through the solution may be regulated to about 2 minutes, and after washing may be exposed to an oven temperature of about 250 C. for about 3 minutes to firmly set the filament.

It is to be understood that in the foregoing examples the water component is added in varying amounts to assist in the formation of the viscous material and that the Water does not form a part of the reaction and may be drawn off prior to extrusion where used in considerable excess. For example, at higher molecular Weights of the dextran a larger amount of water is desirable to secur complete dispersion of the resin in the deX-tran. Thus the viscous mass may be formed by completely solving both primary constituents and heating the solution at about C. to boil off sufiicient water to form the required-viscous extrusion material. Temperatures of C. must not be exceeded however as premature polymerization may then occur.

It will be understood that while there have been given herein certain specific examples of the practice of this invention, it is not intended thereby to have this invention limited to or circumscribed by the specific details of materials, proportions or conditions herein specified, in View of the fact that this invention may be modified according to individual preference or conditions without necessarily departing from the spirit of the disclosure and the scope of the appended claims.

I claim:

A filament having a dextran base comprising the acid reaction product of dextran and a water soluble resin selected from the group consisting of urea formaldehyde, melamine formaldehyde and their ethers.

2. A filament having a dextran base comprising the acid reaction product of dextran having a molecular weight in the range of 50,000 to three million and a water soluble resin selected from the group consisting of urea formaldehyde, melamine formaldehyde and their ethers.

3. A filament having a dextran base comprising the acid reaction product of dextran and a water soluble urea-formaldehyde resin.

4. A filament having a dextran base comprising the acid reaction product of dextran and a. water soluble melamine-formaldehyde resin.

5. A filament having a dextran base comprising the acid reaction product of dextran and an alkylated urea formaldehyde resin.

6. A filament having a dextran base comprising the acid reaction product of dextran and an alkylated alkyloi melamine formaldehyde resin.

7. A filament having a dextran bas comprising the acid reaction product of dextran and a moth ylated methylol melamine formaldehyde resin.

8. A filament having a dextran base comprising the acid reaction product of dextran having an average molecular weight of 100,000, and a water soluble urea formaldehyde resin.

9. A filament having a dextran bas comprising the acid reaction product of dextran having an average molecular weight of 350,000, and a water soluble melamine formaldehyde resin.

10. A filament having a dextran base comprising the acid reaction product of dextran having an average molecular weight of 350,000, and a water soluble alkylated urea formaldehyde resin.

11. A method of producing a filament from a dextran base wherein dextran is reacted with a water soluble resin selected from the group consisting of urea-formaldehyde, melamineformaldehyde and their ethers and the product is extruded to the shape of a filament and treated with a medium having an acid reaction to form the said filament.

12. A method of producing a filament from extran base wherein dextran having an average molecular weight of 100,000 is reacted with a water soluble urea formaldehyde resin and the product is extruded to the shape of a filament and treated with acetone to form the said fila ment.

13. A method of producing a filament from a dextran base wherein dextran having an average molecular weight of 350,000 is reacted with a Water soluble melamine formaldehyde resin and the product is extruded to the shape of a filament and treated with an acidified alcohol to form the said filament.

14. A method of producing a filament from a dextran base wherein dextran having an average molecular weight of 350,000 is reacted with a water soluble alkylated urea formaldehyde resin and the product is extruded to the shape of a filament and treated with acetic acid with a normality of approximately 0.1 to form the said filament.

15. A method of producing a filament from a dextran base comprising the steps of forming an aqueous viscous mass of dextran and a water soluble resin selected from the group consisting of urea-formaldehyde, melamine-formaldehyde and their ethers, extruding the mass into filamentary form, setting the filament in an acidic bath, and heating the said filament.

16. A method of producing a filament from a dextran base comprising the steps of forming to the shape of a filament an aqueous viscous mass of dextran and a water soluble resin selected from the group of urea-formaldehyde, melamine-formaldehyde and their ethers, and the polymerization of which is facilitated under acidic conditions, passing the filament through an acid to set the mass, and thereafter the filament at a temperature in the range of about 200 to 250 C.

17. A method of a dextran base comprising the steps of forming mass of dextran and urea formaldehyde in substantially equal proportions by weight, passing the same through a bath having an acid reaction, and thereafter heating the said filament at a temperature of about 200 C.

18. A filament comprising the acid reaction product of about 85 parts by weight of dextran and about 70 parts by weight of melamine formaldehyde.

19. A filament comprising the acid reaction product of about 60 parts by weight of dextran and about 50 parts by weight of urea formaldehyde.

20. A filament comprising the acid reaction product of about 40 parts by weight of dextran and about parts by weight of methylated methylol urea formaldehyde.

No references cited. 

11. A METHOD OF PRODUCING A FILAMENT FROM A DEXTRAN BASE WHEREIN DEXTRAN IS REACTED WITH A WATER SOLUBLE RESIN SELECTED FROM THE GROUP CONSISTING OF UREA-FORMALDEHYDE, MELAMINEFORMALDEHYDE AND THEIR EHTERS AND THE PRODUCT 